The Forerunner 235 uses the Garmin own Elevate optical sensor to measure heart rate at the wrist, giving you the option to run without a strapSame physical size as Forerunner 225 but with 44% larger visible screenFeaturing a more efficient battery - 9 days in smartwatch mode and 11 hours in training modeIts colourful gauge identifies your heart rate zone and beats per minute in real timeA built-in accelerometer captures distance and pace data when you are running on an indoor track or treadmillOnce you are done running, it doubles as an activity tracker, counting your steps and calories throughout the dayForerunner 235 offers connected features like automatic uploads to Garmin Connect, our free online community where you can save, plan and share your activitiesAdditional connected features include live tracking, which allows your friends to follow you and see your stats in real timeIf you run with headphones, audio prompts will keep you on pace with lap and lap timesCompatibility with Connect IQ will allow you to customise your watch with free downloadable watch faces, widgets, applications and data fieldsGPS and GLONASS satellite location options for fine tuning and fast location fixes in new areasBike speed/cadence sensor compatibleComes with USB charging clip and manual